xamarin - developing iOS app without a mac?

pretty sure the answer is yes (98% sure on that), you need a mac.

here's a great place to get started.

https://mva.microsoft.com/en-US/training-courses/xamarin-for-absolute-beginners-16182?l=WeOu5rtJC_405846048

sorry i'm not sure what the minimum requirements would be, but i wouldn't expect them to be very high, so i'd just pick up a used macbook.

Have a look at the partnership between MIcrosoft and MacInCloud. You can get a Mac build server for $30/month. They have Xamarin support. I havent used this service, but might be worth a try.

http://www.macincloud.com/
https://blogs.msdn.microsoft.com/visualstudioalm/2015/11/18/macincloud-visual-studio-team-services-build-and-improvements-to-ios-build-support/

You can install OS X on Vmware and take advantage of the OS X features on a pc. It's been a while that Apple has allowed virtualization of OS X and so it's completely legal.

Checkout vmware team's opinion on virtualizing OS X:
https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1000131

That's an interesting option. However, in terms of the licensing, just be aware that the VMWare page says:

The End User License Agreement (EULA) for Apple Mac OS X legally and explicitly binds the installation and running of the operating system to Apple-labeled computers only.

I don't mind putting an apple sticker on my dell laptop :)

Hahahahahaha... nice one @websss!

To clarify .. being 100% legal you cannot install OSX on VMWare on non-Apple hardware (sticker on a Dell will not qualify ;-) ).  
The declaration on the VMWare website is correct.  That being said it can be done, it'll just void Apple warranty etc.

The simplest OSX options are the the Mac Mini .. basic model for $499 would suffice
http://www.apple.com/mac-mini/
or cloud based with MacInCloud (or a similar service)

When developing apps one often runs into hardware specific issues which aren't found via emulation (for example: 1) physical input sizes being hard to touch, 2) swipe or tap gestures not working correctly, 3) hardware data not matching expected results (ie accelerometer, gps)). I would also recommend that you buy a target device to test on. Fortunately used iDevices are easy and relatively cheap to obtain.

Thanks
I have an iPad and iphone 4s I can use for testing  

Am I correct in assuming a VMware Mac on a Windows pc can be used as a build server for xamarin?

have it all setup but not quite working as I cannot ping into the mac... but almost got there!